Hyalomma anatolicum as the Main Infesting Tick in an Important Livestock Rearing Region, Central Area of Iran.

Background
This study was carried out to determine the infestation of domestic ruminants to ticks in an important livestock-rearing region, located in central part of Iran.


Methods
Ticks were collected from cattle, sheep, and goats and then were identified with appropriate identification keys to species level in two different ecological regions of plains and mountain in 4 seasons in 2015.


Results
Totally 492 ticks from cattle, sheep, and goats in 34 herds were collected. Totally, 18.53% of domestic animals were infected by ticks. All ticks were belonged to family Ixodidae and classified into three genera and six species comprising Hyalomma anatolicum (38.83%), Hy. Asiaticum (23.37%), Hy. marginatum (2.85%), Hy. sp. (3.45%), Rhipicephalus sanguineus (14.02%) and Haemaphysalis sulcata (10.98%). Sex ratio of the collected specimens showed 241 (48.99%) male, 219 (44.51%) female and 32 (6.5%) nymph.


Conclusion
Studied area is important for production of livestock and dairy products. Annually, many livestock products are exported to other parts from this region; therefore, it is very important to identify the infection rate of tick-borne diseases as well as safety factors on livestock.


Introduction
Ticks are ectoparasites, living by hematophagy on the blood of birds, mammals, reptiles, and amphibians. Some of tick species act as vectors of a broad range of pathogens of domestic animals like sheep and goats and are responsible for damage directly due to their feeding behavior (1). Ticks can transmit a variety of diseases such as Crimean Congo hemorrhagic fever (CCHF), anaplasmosis, babesiosis, rickettsiosis, borreliosis and ehrlichiosis in which CCHF is considered as one of the most deadly arboviruses (2). Tick studies in Iran were initiated by Delpy and then Later, Abbasian-Lintzen and Mazlum compiled a list of ticks collected from domestic ani-mals. In another investigation, data for ixodid ticks were taken from mammals, mainly rodents in different locations of the country. Ticks parasitizing wild sheep and goats were studied in the country and currently, prevalence of ticks was studied in the northwest and the western part of Iran (3,4). Distribution of various species of ticks on domestic animals in some geographical locations of Iran was studied (5). Due to the importance of ticks and tick-borne diseases, there are many reports on epidemiology, distribution and medical importance of different ticks through the country (6,7). Due to geographical location, climate, topography and diversity, Golpayegan County is a major hub of livestock rearing in Iran. This county is located in Isfahan Province, central part of the country. The current study aimed to investigate bio-systematically the distribution of ticks based on their genus and species. Due to the importance of animals' husbandry and dairy products, understanding the distribution of ticks pro-vides important data for preventing tickassociated diseases in livestock. Study on distribution of ticks, which infect the domestic ruminants provide a clue for tick-borne diseases in the region (8). This study was conducted to determine the tick infestation status in domestic ruminants in Golpayegan County, Isfahan Province, central part of Iran in 2015.

Study area
Isfahan Province covers an area of approximately 107000 km 2 . Golpayegan County (33°27', 50°18' E) is located in this province (Fig. 1). The mean elevation of this city is 1800m above sea level and the average annual rainfall is 300 mm. According to the census of the veterinary office in 2014, Golpayegan County has about 25000 cattle, 105000 sheep, and 15000 goats.

Tick collection
From July 2014 to June 2015, 16 villages in two different ecological regions including 12 plains (70%) and 4 mountain (30%) regions were randomly selected as the study area (Fig. 1).
We used the formula ) for calculation of the sample size (9,10). In total, 437 livestock including 208 sheep, 55 goats, and 174 cattle were selected randomly and examined individually for tick infestation. Thirty minutes were spent for each flock to collect ticks. The entire body of each animal including ears, nape of the neck, perineum, scrotum, and the tail base was inspected for the presence of tick species. Collected ticks were kept alive in labeled vials and then transferred to the laboratory in School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran for species identification by using the appropriate identification keys (11,12).
Overall, 447 (90.85%) tick species collected from plateau zone and the rest were from mountain zone. The species diversity of hard ticks in plateau areas was more than mountain area.  Table 4.   (17) and 27% in Kashan located in central part of Iran (18,19). The infection rates based on the animal host is consistent with the results of Golestan (15) and Tehran (16), but it is contrary to results on different hosts in different geographical areas. The controversy in the results might be associated to different parameters including the quality of animals' nourishment, the variance in the cattle's sensitivity to different ticks' strains, cattle's hygiene and applying preventive strategies including cattle's spraying and anti-ticks bath. The mean number of ticks on each animal was low (about 6.07 ticks per animal). The occurrence of ticks on cattle, sheep, and goats were 61.18%, 30.7% and 8.12% respectively. Through viewpoint of study were conducted about tick infestation of livestock, the percentage of tick per animal in different geographical areas of Iran such as Golestan (15), Mazandaran (10), Darreh Shahr (17), Isfahan (18,19), Kermanshah (20) and (5), infestation rate on cattle with studies in Ilam (17) and in four different zoogeographical areas in Iran (5) was coincided but in other parts of Iran the highest infestation rate related to sheep host. Three genera were collected in this investigation where the Hyalomma species comprised 75% of our collected samples comprising Hy. anatolicum, Hy. marginatum and Hy. asiaticum. These results are in agreement with the study conducted in West Azerbaijan, Zabol, Ghaen, Abdanan, Esfahan, Ardebil, Sarepole-zahab, Ghom and Meshkin-Shahr districts (3,6,9,19,(21)(22)(23)(24)(25)(26). Hyalomma ticks were dominant in the investigated area. In another study directed in Golestan and Ghazvin, Rhipicephalus (10,15,27) and in Guilan, Boophilus  (14) and Hamedan (4). Currently, in an investigation conducted in northwestern Iran, the most of ticks were collected in summer and spring respectively (39).
In the present study, most of tick species were collected from cattle (dominant species: Hy. anatolicum) in spring and Ha. sulcata were found on sheep in winter. The results of prevalence of isolated ticks from infested ruminants related to different seasons reveal that the most number of tick species are in plateau zone and spring season.

Conclusion
Studied area is considered as one of the most important centers of agriculture and livestock rearing in the region. This district is also important for dairy products. Because of region's landscape, weather, and livestock, the dairy products have earned a high rank in the county. Annually, many livestock products are exported to other parts of Iran; finally, the identification of the infection rate of tick-borne diseases as well as safety factors on livestock is suggested.

Ethical considerations
Ethical issues (Including plagiarism, informed consent, misconduct, data fabrication and/or falsification, double publication and/or submission, redundancy, etc.) have been completely observed by the authors.